Flexible antiferroelectric (AFE) Pb0.94La0.04Zr0.97Ti0.03O3 (PLZT) thick‐film capacitors were fabricated on nickel foil substrates using sol‐gel method. The thick PLZT film shows pure perovskite phase with dense microstructure. The discharge energy‐storage properties of the thick PLZT film are directly evaluated by the resistance‐inductance‐capacitance (RLC) circuit. The maximum value of the discharge energy‐storage density (Wdis) is 15.8 J/cm3 at 1400 kV/cm and 90% of the corresponding energy is released in a short time of about 250 ns. In addition, the Wdis and discharge time could be adjusted by the bent radius of the film, which provides a simple and feasible solution for the regulation of the electrical performance. Furthermore, the flexible AFE film exhibits good mechanical properties under cycling tests with bending radii down to 2.5 mm and 1500 rounds. This work shows a critical significance in fabricating flexible AFE capacitors for application in modern electronics and electrical power systems.

Developing a general strategy to efficiently exfoliate transition metal dichalcogenide (TMD) electrocatalysts would be significantly beneficial for the electrocatalytic hydrogen evolution reaction (HER) from water splitting. However, there are several challenges in the production of two-dimensional (2D) TMDs, including the complicated fabrication process, high defect rate, and low production yield. Herein, we developed a general applicable mild organic molecular intercalator-assisted liquid-phase exfoliation method to produce TMD nanosheets in a large scale. The as-prepared ultrathin WSe2, MoSe2, WS2, and MoS2 nanosheets have a 2D nanosheet structure with a thickness of ∼3 nm and lateral size in a few hundred nanometers. This mild intercalation method can avoid introducing harsh exfoliation conditions used in conventional liquid-phase exfoliation, electrochemistry exfoliation, and lithium intercalation, thus resulting in high-quality exfoliation of TMD crystals. Additionally, benefiting from superior intrinsic electrical conductivity, unique 2D structure, and highly exposed active sites, the exfoliated WSe2 and MoSe2 nanosheets exhibited excellent catalytic activity for HER in acid with overpotentials of 223 and 225 mV at a current density of 10 mA cm–2 and low Tafel slopes of 64 and 65 mV dec–1, respectively.

The development of lead-free dielectric materials with environmental friendliness has been of great significance to enhance the capability of electronic devices owing to their excellent energy storage properties (ESPs). Learning from the doping mechanism of ABO 3 , moderate defects such as oxygen vacancies ( ″ V O ) produced by chemical modification are beneficial to increase the ESP of the dielectric materials. Hence, we propose an innovative design strategy to stimulate the potential capability of energy storage in BaTiO 3 (BT)-based ceramics by B-site [Li Ti − V o ] − defect dipole engineering. A systematic analysis proves that the Li-occupied Ti-site in the unit cell of BT moves along the [001] direction. In this case, Li + forms the defect dipoles with neighboring ″V O , producing defect polarization as the interelectric field. It resists the applied electric field, resulting in smaller remnant polarization (P r ) and dielectric breakdown strength (BDS) to optimize the ESP. As expected, the Li + -doped BT ceramic through defect dipole engineering exhibits a low P r of 2.29 μC/cm 2 and a giant gap in the polarization (ΔP) up to 35.73 μC/cm 2 , which is superior to the pure BT ceramic (P r of 19.98 μC/cm 2 and ΔP of 18.86 μC/cm 2 ) and other element (such as Zr 4+ and Sr 2+ )-doped BT materials. More importantly, it satisfies the requirement of a larger BDS of 140 kV/cm with the corresponding recoverable energy storage density of 1.11 J/cm 3 . Our research focuses on the Bsite defect dipole engineering, which is expected to benefit energy storage material design.

The great challenge facing additive manufacturing is that the available high-performance 3D printing materials can hardly keep up with the rapid development of new additive manufacturing technology. Then, the commercial resins available in the market have some problems, such as poor thermal stability, insufficient light-curing degree, and large shrinkage after curing, which need to be solved urgently. This study reports a photocurable polyimide ink for digital light processing (DLP) 3D printing to prepare controllable 3D structures with high thermal stability, low shrinkage, and excellent comprehensive properties. In this study, pyromellitic dianhydride and diaminodiphenyl ether, the Kapton polyimide with the highest performance synthesized so far, were selected as raw materials, and 2,2′-bis(3,4-dicarboxylic acid) hexafluoropropane dianhydride containing fluorine was introduced to modify the branched-chain structure. The polyimide was prepared by one-step imidization, and then the graft with photocurable double bonds and certain functions was grafted by reaction of glycidyl methacrylate with phenolic hydroxyl groups. In this work, the solubility of the synthesized oligomer polyimide in organic solvents was greatly increased by combining three methods, thereby allowing the formation of ink for photocuring 3D printing, and the ink can be stacked to form low-shrinkage polyimide with complex controllable shape. Polyimide printed by DLP can produce complex structures with good mechanical character and thermal stability and small shrinkage. Therefore, the polyimide prepared in this study is considered to be a resin of great commercial possibility. In addition, due to its properties, it has important development potential in some fields with high demand for thermal stability, such as high-temperature cooling valves, aerospace, and other fields.